The calcium-binding protein S100A1 binds to titin's N2A insertion sequence in a pH-dependent manner.

ABSTRACT: Titin is the third contractile filament in the sarcomere, and it plays a critical role in sarcomere integrity and both passive and active tension. Unlike the thick and thin filaments, which are polymers of myosin and actin, respectively, titin is a single protein that spans from Z-disk to M-line. The N2A region within titin has been identified as a signaling hub for the muscle and is shown to be involved in multiple interactions. The insertion sequence (UN2A) within the N2A region was predicted as a potential binding site for the Ca2+-binding protein, S100A1. We demonstrate using a combination of size exclusion chromatography, surface plasmon resonance, and fluorescence resonance energy transfer that S100A1 can bind to the UN2A region. We further demonstrate that this interaction occurs un

SUBMITTER: Apel SI 

PROVIDER: S-EPMC11687307 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature